Age, growth, and condition of the Mud River crayfish Orconectes ronaldi Taylor 2000 (Decapoda: Cambaridae)

2015 ◽  
Vol 21 (1) ◽  
pp. 115-121
Author(s):  
Hannah Noss ◽  
Wendy Anderson ◽  
Thomas P. Simon
Keyword(s):  
Statistical Difference ◽  
Sexually Dimorphic ◽  
Allometric Growth ◽  
Native Range ◽  
South Central ◽  
Length Width ◽  
Wet Weight ◽  
Native Crayfish ◽  
Sexually Mature ◽  
Crayfish Species

Abstract The Mud River crayfish, Orconectes ronaldi Taylor, is a native crayfish species found in the Midwestern United States in Kentucky and Indiana. Length-weight relationship, body morphometric relationship, and condition within the species native range in south-central Indiana were studied. Growth, size relationships based on gender, sexual phase for adults and juveniles and chelae-length/width relationships were used to interpret patterns in sexual dimorphism. Carapace length (CL)–wet weight (Wwt) relationships for all genders (i.e., male, female, juvenile) and all male forms (form I and II) had positive allometric growth. Male individuals were not significantly heavier than females of the same length. The maximum length and weights of males (35.1 mm CL) were longer and heavier (11.8 g) than the longest female (31.5 mm) weighing 8.3 g. No statistical difference in mean weight was observed; however, this is attributed to the accelerated development of the chelae in sexually mature form I males, whereas chelae of females grow slower throughout life. Chelae length was significantly different between male form II and male form I, and male form II and females (P = 0.004, and P <0.001, respectively). The relatively longer chelae of form I and form II males are due to sexually dimorphic change.

scholarly journals Growth pattern of freshwater bivalve mollusk Lamellidens marginalis (Lamarck, 1819) from the northwest Bangladesh

2019 ◽  
Vol 27 ◽  
pp. 121-132
Author(s):  
DA Nahar ◽  
MR Islam ◽  
MS Islam ◽  
S Jasmine ◽  
MMR Mondol
Keyword(s):  
Growth Pattern ◽  
Fishery Management ◽  
Freshwater Mussel ◽  
Freshwater Ecosystem ◽  
Allometric Growth ◽  
Freshwater Bivalve ◽  
Shell Weight ◽  
Tissue Weight ◽  
Length Width ◽  
Sustainable Fishery

Growth, morphometry and length-weight relationships of the freshwater mussel Lamellidens marginalis (Lamarck, 1819) was studied during January 2014 and May 2015. Sampling was carried out monthly and a total of 560 specimens were collected from Rajshahi district, northwest of Bangladesh. The recorded length -breadth and length-width relationships were B = 0.179 + 0.475L and W = 0.196 + 0.3163L respectively. The length-total weight, length-wet tissue weight, length-dry tissue weight, length-shell weight, length-dry shell weight relationships were W = 0.1241L2.9066, W = 0.0524L2.7377, W =0.0116L2.7849, W = 0.0533L2.9178 and W = 0.0391L3.0386 respectively. Monthly b values of length-lengths and length-weights relationships indicated a negative allometric growth pattern except length-shell weights relationships which showed an isometric growth of the mussel. This study is the first report on growth pattern of Lamellidens marginalis from Bangladesh and the results would be useful for fishery managers to impose adequate regulations for a sustainable fishery management of this species in the freshwater ecosystem in Bangladesh. J. bio-sci. 27: 121-132, 2019

Vulnerability of Southwest Iberian amphibians to an introduced crayfish, Procambarus clarkii

2005 ◽  
Vol 26 (3) ◽  
pp. 293-303 ◽  
Author(s):  
Rui Rebelo ◽  
Maria João Cruz
Keyword(s):  
Procambarus Clarkii ◽  
Larval Survival ◽  
Bufo Bufo ◽  
Microhabitat Use ◽  
Amphibian Species ◽  
Embryo Survival ◽  
Breeding Habitats ◽  
Mesocosm Experiments ◽  
Native Crayfish ◽  
Crayfish Species

AbstractThe introduction of predators in amphibian breeding habitats may contribute to the decline or extinction of amphibian populations. Procambarus clarkii, a North American crayfish, was recently introduced in the Iberian Peninsula, being now quite abundant in the southwest, a region with no native crayfish species and where 13 amphibian species may be found. We performed mesocosm experiments to evaluate the vulnerability of amphibian embryos and larvae from those species to P. clarkii. Despite the presence of alternative food (vegetation and leaf litter), embryo survival in the presence of P. clarkii was low for all species except Bufo bufo. However, newly hatched B. bufo tadpoles were readily consumed. P. clarkii reduced larval survival in all species, with those species that in nature have few contacts with predators at the larval stage suffering the highest mortalities. Most larvae reduced their activity and/or altered microhabitat use in the presence of P. clarkii, but these behavioural modifications did not lead necessarily to a low vulnerability to predation.

Relaxed attitude towards spreading of alien crayfish species affects protection of native crayfish species: case studies and lessons learnt from a Fennoscandian viewpoint

2020 ◽  
Vol 25 (1) ◽  
pp. 39-46
Author(s):  
Japo Jussila ◽  
Lennart Edsman
Keyword(s):  
Competitive Advantage ◽  
Pacifastacus Leniusculus ◽  
Astacus Astacus ◽  
Signal Crayfish ◽  
Aphanomyces Astaci ◽  
Noble Crayfish ◽  
Native Crayfish ◽  
Chronic Carrier ◽  
Highly Virulent ◽  
Crayfish Species

Abstract The spreading of the alien signal crayfish (Pacifastacus leniusculus) is posing an ongoing threat to native European crayfish species in Fennoscandia, like the native noble crayfish (Astacus astacus). The signal crayfish is commonly a chronic carrier of the crayfish plague (Aphanomyces astaci), thus, in addition to being more competitive than noble crayfish, it also has a competitive advantage in this disease over the noble crayfish. The challenges rising from the introduction of the alien signal crayfish to Sweden, Finland and finally also Norway, are similar in nature. The licensed and unlicensed spreading of this species also has a similar history in these countries. In this paper we describe some of the patters of the spread of alien signal crayfish and highlight the detrimental nature of an alien crayfish, accompanied by a highly virulent disease, to native Fennoscandian crayfish and also to native Fennoscandian ecosystems. A halt to the further spreading of alien signal crayfish in Fennoscandia is the only means to ensure successful conservation outcomes for the noble crayfish.

Study on the Physical and Chemical and Mechanical Pulping Characteristic of Cotton Stalk Fiber

2014 ◽  
Vol 884-885 ◽  
pp. 158-161
Author(s):  
Li Xia Li ◽  
Hai Tao Chen
Keyword(s):  
Test Method ◽  
Cotton Stalk ◽  
Physical Chemical ◽  
Significant Difference ◽  
Length Width ◽  
Wet Weight ◽  
Correlation Strength ◽  
Block Test ◽  
Physical And Chemical ◽  
Composition Changes

Straw resource was tremendous, however it was utilized poorly. So the research of physical, chemical and mechanical pulping properties of cotton stalk fiber laid the foundation for utilization of cotton stalk. Morphology of cotton stalk fiber was determined by Feica microscope, the length, width and length to wide ratio were analyzed by SPSS 17.0. Chemical composition changes of cotton stalk fiber after mechanical process were analyzed by applying Block test method with Design-expert 6.0.10.The result present that composition of fiber had significant difference. Hemicellulose decreased by 1.68 %, cellulose decreased by8.85 %, lignin increased by 5.87 %. Beating degree was positively correlated with the pulping time, beating time and wet weight were a negative correlation. Strength of cotton stalk fiber was positively with the gramme, and strength was 8.5 N when gramme was 60 g/m2.

scholarly journals Changes in the sizes of the kidney after contralateral nephrectomy in the experiment

2018 ◽  
Vol 24 (3) ◽  
pp. 52-57
Author(s):  
V.M. Monastyrskyi
Keyword(s):  
Postoperative Period ◽  
Left Kidney ◽  
Abdominal Cavity ◽  
White Male ◽  
Male Rats ◽  
Control Group ◽  
Close Relationship ◽  
Length Width ◽  
Sexually Mature ◽  
Experimental Group

The evaluation of renal measurements such as length, width and thickness, volume is important in the diagnosis and treatment of many renal disorders, since there is a close relationship between the sizes of the kidneys and its function. The purpose of the study was to establish and compare during the postoperative period changes in the mass and sizes of the kidney left after nephrectomy in the sexually mature male rats. An experimental study was carried out on 84 sexually mature white male rats weighing 178-194 grams. Animals were divided into two groups: control (42 rats) and experimental (42 rats). In the control group, the animals under ketamine anesthesia were followed by an abdominal cavity dilution, after which the abdominal wall was applied in a row. All animals of the experimental group performed surgical intervention – nephrectomy of the left kidney. The animals were withdrawn from the trial by intra-pleural administration of thiopental-sodium 50 mg/kg after 7, 14, 21, 30, 90 days after nephrectomy. Macroscopic evaluation and description of the kidneys of animals was performed after their removal. Their weight was determined on the laboratory scale of HLR-200 up to 0.1 mg, and the length, width and thickness of the organ were measured with the help of a caliper to an accuracy of 0.05 mm. Calculated the volume of the kidney. The statistical analysis of the obtained results was carried out using the program STATISTICA 5.5 using parametric methods for evaluating the results. It was established that the mass, length, width, thickness and volume of the kidney of animals in the experimental group, as compared with the control group, were statistically significantly higher in all terms of observation. The fraction of the growth of the width and thickness of the single kidney of animals in the experimental group compared with the control animals in the animals was statistically significantly greater than the proportion of kidney growth during the postoperative period. It was found that the largest increase in the mass and thickness of the kidney, as compared with the control group, was observed after 30 days of the postoperative period, and the greatest increase in the length and width of the kidney, as compared with the control group, was observed after 14 days of the postoperative period.

scholarly journals Disease risks associated with the importation and release of non-native crayfish species into mainland Britain

2012 ◽  
Vol 16 (1) ◽  
pp. 1-15 ◽  
Author(s):  
M Longshaw ◽  
KS Bateman ◽  
P Stebbing ◽  
GD Stentiford ◽  
FA Hockley
Keyword(s):  
Disease Risks ◽  
Native Crayfish ◽  
Crayfish Species

DEXAMETHASONE IN THE MANAGEMENT OF KEROSENE PNEUMONIA

PEDIATRICS ◽  
1974 ◽  
Vol 53 (1) ◽  
pp. 86-90
Author(s):  
J. Wolfsdorf ◽  
Dip. Paed. ◽  
H. Kündig
Keyword(s):  
Body Weight ◽  
Aspiration Pneumonia ◽  
Inflammatory Process ◽  
Statistical Difference ◽  
Dry Weight ◽  
Control Group ◽  
Lung Weight ◽  
Group Iii ◽  
Group I ◽  
Wet Weight

The efficacy of steroids in the treatment of acute aspiration pneumonia, following intratracheal kerosene instillation in primates, was examined. Forty Chacma baboons were utilized in three groups: group I (normal animals), group II (animals receiving 0.3 ml/kg intratracheal kerosene alone, control group), and group III (animals receiving 0.3 ml/kg intratracheal kerosene plus pre- and posttreatment with 5 mg/kg IMI dexamethasone). The lungs from all animals were examined macroscopically and microscopically and their lung wet weight-dry weight and lung weight-body weight ratios determined. On all parameters utilized, the lungs from groups II and III were different from group I. No statistical difference, however, could be detected between values obtained from groups II and III. These data tend to support the contention that steroids, even when given early, and in large doses, in the course of kerosene pneumonitis, do not alter the acute inflammatory process that occurs.

A new species of Helmutkunzia Wells & Rao, 1976 from an intertidal sandy beach in Xiamen, China and proposal of Pseudobalucopsylla gen. nov. (Copepoda, Harpacticoida, Miraciidae)

Zootaxa ◽  
2021 ◽  
Vol 5051 (1) ◽  
pp. 487-505
Author(s):  
FANGHONG MU ◽  
RONY HUYS
Keyword(s):  
New Species ◽  
Sandy Beach ◽  
Relative Length ◽  
Width Ratio ◽  
Sexually Dimorphic ◽  
Nicobar Island ◽  
Galapagos Archipelago ◽  
The Pacific ◽  
Length Width ◽  
A New Species

A new species of the genus Helmutkunzia Wells & Rao, 1976 (Miraciidae) is described from specimens collected from an intertidal sandy beach in Xiamen, Fujian Province, China. Helmutkunzia xiamenensis sp. nov. differs from its two congeners by the length/width ratio of the female P5 exopod, the number or length of the setae on the sexually dimorphic P2 endopod in the male and the relative length of the spines on the endopodal lobe of the male P5. The Chinese species is morphologically closest to H. variabilis Wells & Rao, 1987 from the Andaman and Nicobar island chain. Females of both species can readily be differentiated by the relative length of the P5 exopod while males can be differentiated by the length of the armature elements on P2 enp-2 and the endopodal lobe of P5. The genus Balucopsylla Rao, 1972 is reviewed, resulting in the proposal of Pseudobalucopsylla gen. nov. to accommodate the type species Balucopsylla triarticulata Wells & Rao, 1987 and three new Indo-Pacific species previously identified with it: P. obscura sp. nov. from the Andaman Islands, P. costaricensis sp. nov. from the Pacific coast of Costa Rica and P. mielkei sp. nov. from the Galápagos archipelago. A key to species of Pseudobalucopsylla sp. nov. is provided.  

Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: analysis of reproductive tracts

1993 ◽  
Vol 71 (9) ◽  
pp. 1811-1815 ◽  
Author(s):  
James L. Bodkin ◽  
Dan Mulcahy ◽  
Calvin J. Lensink
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Enhydra Lutris ◽  
Sea Otters ◽  
Older Mothers ◽  
South Central ◽  
In Situ Observations ◽  
Reproductive Rates ◽  
Sexually Mature

We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oil spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% at age 2 to 78% at age 5 and remained relatively stable (75–88%) through to age 15. The sex ratio (♀:♂) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than 8 tended to produce more female fetuses, while older mothers did not. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similar to those reported in the literature based on in situ observations of marked individuals.

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